WO2018008551A1

WO2018008551A1 - Abrasive material

Info

Publication number: WO2018008551A1
Application number: PCT/JP2017/024164
Authority: WO
Inventors: 裕昭井上; 幸二竹村; 友樹岩永; 高木　大輔; 啓佑笹島; 歳和田浦
Original assignee: スピードファム株式会社; バンドー化学株式会社
Priority date: 2016-07-08
Filing date: 2017-06-30
Publication date: 2018-01-11
Also published as: JP2018001392A; TW201801857A; TWI737760B; JP6859035B2; CN109195749A

Abstract

The purpose of the present invention is to provide an abrasive material which can has relatively high machining efficiency while inhibiting damage to a workpiece caused when the workpiece falls in a groove, etc. The present invention is an abrasive material that comprises a base material, and an abrasive layer stacked on a surface side of the base material, and that is characterized in that: the abrasive layer contains abrasive grains and a binder for the abrasive grains, and includes multiple kinds of abrasive parts which show different abrasion amounts in the Taber abrasion test; a first abrasive part which shows the smallest abrasion amount among the multiple kinds of abrasive parts is surrounded by other abrasive parts; the ratio of the abrasion amounts of the other abrasive parts to the abrasion amount of the first abrasive part is at least 3; and the ratio of the area occupied by all the abrasive parts in the abrasive layer is 15-100% inclusive. The ratio of the area occupied by the first abrasive part in the abrasive layer is preferably 3-16% inclusive. The first abrasive part may contain diamond abrasive grains, and the content of the diamond abrasive grains in the first abrasive part is preferably 1-20 vol% inclusive.

Description

Abrasive

The present invention relates to an abrasive.

In recent years, electronic devices such as hard disks have been refined. Glass, sapphire, or the like is used as a substrate material for such electronic devices in consideration of rigidity, impact resistance, and heat resistance that can be reduced in size and thickness. For processing such a substrate, a fixed abrasive is generally used.

Incidentally, in the above substrate processing, improvement of processing efficiency is required. As an abrasive capable of increasing the processing efficiency of substrate processing, for example, an abrasive in which a plurality of independent abrasive structures are formed as an abrasive layer on the surface of a base sheet has been proposed (Japanese Patent Laid-Open No. 2009-72832). See the official gazette). In this polishing material, the polishing pressure is increased and the grinding force is improved by reducing the area ratio of the polishing surface of the polishing structure to the polishing layer and reducing the area of the polishing surface that receives a polishing load applied during polishing.

In the conventional abrasive, the area ratio is controlled by providing grooves between a plurality of polishing structures. For this reason, in order to reduce the area ratio and improve the grinding force, it is necessary to widen the groove width between the polishing structures. When the groove width is widened in this way, when the end portion of the substrate (workpiece) crosses the groove during polishing, the end portion of the substrate tends to be inclined toward the base sheet side. For this reason, the frequency | count that a board | substrate will be damaged increases because a board | substrate is hooked on the side surface upper part of a groove | channel, or falls in a groove | channel.

JP 2009-72832 A

The present invention has been made in view of such inconveniences, and an object of the present invention is to provide an abrasive that can achieve a relatively high processing efficiency while suppressing damage caused by dropping of a workpiece into a groove or the like.

The invention made to solve the above problems is an abrasive comprising a substrate and a polishing layer laminated on the surface side of the substrate, the polishing layer containing abrasive grains and a binder thereof, In addition, a plurality of types of polishing portions having different wear amounts in the Taber abrasion test are provided, and the first polishing portion having the smallest wear amount among the plurality of types of polishing portions is surrounded by another polishing portion, and the first polishing is performed. The ratio of the wear amount of the other polishing portion to the wear amount of the portion is 3 or more, and the occupation area ratio of the entire polishing portion in the polishing layer is 15% or more and 100% or less.

The abrasive includes a first polishing portion and another polishing portion surrounding the first polishing portion, and the ratio of the wear amount of the other polishing portion to the wear amount of the first polishing portion in the Taber wear test is the above It is more than the lower limit. For this reason, when polishing is performed using the abrasive, the other polishing portions surrounding the first polishing portion are worn first. As a result, in a relatively short time from the start of polishing, a step is formed between the first polishing portion and the other polishing portion that makes the other polishing portion low. In addition, since the abrasion of the polishing portion proceeds mainly in the first polishing portion and the other polishing portions due to the spilling of abrasive grains, the workpiece is polished while maintaining the step. Therefore, since the first polishing portion mainly receives a polishing load applied during polishing, the polishing pressure of the first polishing portion is increased, and thereby the grinding force of the abrasive is increased. Further, in the abrasive, the other polishing portion surrounds the first polishing portion, and the occupation area ratio of the entire polishing portion in the polishing layer is within the above range. For this reason, when the edge part of a to-be-cut body moves between 1st grinding | polishing parts at the time of grinding | polishing, the said abrasive | polishing material can suppress that a to-be-cut body leans to a base material side by said other grinding | polishing part. Therefore, the abrasive can suppress damage caused by dropping into the groove or the like of the workpiece.

The occupation area ratio of the first polishing portion in the polishing layer is preferably 3% or more and 16% or less. By setting the occupation area ratio of the first polishing portion within the above range, the polishing pressure received by the first polishing portion can be increased, and the grinding force of the abrasive can be further improved.

It is preferable that the abrasive grains of the first polishing section are composed of a plurality of types of abrasive grains. As described above, by configuring the abrasive grains of the first polishing section with a plurality of types of abrasive grains, it is possible to improve the grinding force while suppressing an increase in the manufacturing cost of the abrasive.

The first polishing portion preferably contains diamond abrasive grains, and the content of the diamond abrasive grains in the first polishing portion is preferably 1% by volume or more and 20% by volume or less. Thus, by setting the content of the diamond abrasive grains in the first polishing portion within the above range, it is possible to further improve the grinding force while suppressing an increase in the manufacturing cost of the abrasive.

The content of the diamond abrasive grains in the other polishing part is preferably 0.3% by volume or less. Since diamond abrasive grains are hard and have high grinding power, clogging and spilling are less likely to occur even when they come into contact with the workpiece, and are more susceptible to large polishing loads than other abrasive grains. For this reason, by setting the content of diamond abrasive grains in the other polishing portion below the upper limit, it is possible to prevent the polishing load from being applied to the other polishing portion during polishing and to concentrate on the first polishing portion. The grinding power of the abrasive can be improved. The content of the diamond abrasive grains is 0% by volume, that is, the other polishing portion may not contain diamond abrasive grains.

Here, the “abrasion amount in the Taber abrasion test” is a condition in which specimens (average diameter 104 mm, average thickness 300 μm) are prepared, and wear wheel H-18, load 4.9 N (500 gf) using a Taber abrasion tester. This is a value obtained by measuring the mass difference between the test pieces before and after 320 rotations. Further, “the first polishing unit is surrounded by another polishing unit” means that the first polishing unit is located in a closed space formed by the other polishing unit in plan view. In addition, although the said other grinding | polishing part may exist continuously in the outer periphery of closed space, there may exist an intermittent part in the range of 10% or less of the length of a perimeter. When there is an interrupted portion in another polishing portion, the interrupted portion determines an area of the closed space by extrapolation. When there is such an intermittent portion, the first polishing portion may be partially located in the closed space, but the area of the first polishing portion located in the closed space in a plan view is the entire first polishing portion. When 50% or more of the area is occupied, it is determined that the first polishing portion is located in a closed space. Further, the “area of the polishing layer” is a concept including the area of the groove when the polishing layer has a groove.

As described above, the abrasive of the present invention can achieve a relatively high machining efficiency while suppressing damage caused by dropping into the groove or the like of the workpiece.

It is a typical fragmentary top view which shows the abrasives which concern on embodiment of this invention. FIG. 2 is a schematic partial cross-sectional view taken along line AA in FIG. It is a typical fragmentary top view which shows the abrasives different from FIG. FIG. 4 is a schematic partial plan view showing a structure of a polishing portion of an abrasive different from those in FIGS. 1 and 3. FIG. 5 is a schematic partial plan view showing a structure of a polishing portion of an abrasive different from those in FIGS. 1, 3, and 4. FIG. 6 is a schematic partial plan view showing a structure of a polishing portion of an abrasive different from those in FIGS. 1 and 3 to 5. FIG. 7 is a schematic partial plan view showing a structure of a polishing portion of an abrasive different from those in FIGS. 1 and 3 to 6. FIG. 8 is a schematic partial plan view showing a structure of a polishing portion of an abrasive different from those in FIGS. 1 and 3 to 7. It is a typical fragmentary sectional view which shows the abrasive | polishing material which concerns on embodiment different from FIG.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings as appropriate.

The abrasive 1 shown in FIGS. 1 and 2 includes a base material 10, a polishing layer 20 laminated on the front surface side of the base material 10, and an adhesive layer 30 laminated on the back surface side of the base material 10. . The abrasive 1 is used as a fixed abrasive abrasive for substrate processing, for example.

〔Base material〕
The substrate 10 is a plate-like member for supporting the polishing layer 20.

The main component of the substrate 10 is not particularly limited, and examples thereof include polyethylene terephthalate (PET), polypropylene (PP), polyethylene (PE), polyimide (PI), polyethylene naphthalate (PEN), aramid, aluminum, copper and the like. It is done. Among these, PET and aluminum that have good adhesion to the polishing layer 20 are preferable. Moreover, the process which improves adhesiveness, such as a chemical process, a corona process, and a primer process, may be performed on the surface of the base material 10. Here, the “main component” means a component having the highest content, for example, a component having a content of 50% by mass or more, preferably 90% or more.

Further, the base material 10 may have flexibility or ductility. Thus, since the base material 10 has flexibility or ductility, the abrasive 1 follows the surface shape of the workpiece, and the contact area between the polishing surface and the workpiece is increased. Further increase. Examples of the main component of the flexible base material 10 include PET and PI. Moreover, aluminum, copper, etc. can be mentioned as a main component of the base material 10 which has ductility.

Although the shape and size of the substrate 10 are not particularly limited, for example, a square shape having a side of 140 mm or more and 160 mm or less, or an annular shape having an outer diameter of 200 mm or more and 2100 mm or less and an inner diameter of 100 mm or more and 660 mm or less. Moreover, the structure by which the several base material 10 juxtaposed on the plane is supported by a single support body may be sufficient.

The average thickness of the substrate 10 is not particularly limited, but can be, for example, 50 μm or more and 1 mm or less. When the average thickness of the base material 10 is less than the lower limit, the strength and flatness of the abrasive 1 may be insufficient. Conversely, when the average thickness of the substrate 10 exceeds the upper limit, the abrasive 1 becomes unnecessarily thick and may be difficult to handle.

[Polishing layer]
The polishing layer 20 has two types of polishing portions with different wear amounts in the Taber abrasion test. Of the two types of polishing parts, the first polishing part 21 having a small wear amount is surrounded by the second polishing part 22 having a large wear amount. The second polishing parts 22 are separated from each other by the grooves 23 independently of each other. The second polishing unit 22 surrounds one first polishing unit 21, and there is no gap between the first polishing unit 21 and the second polishing unit 22. That is, the first polishing portion 21 and the second polishing portion 22 constitute a convex portion 24.

The lower limit of the average thickness of the polishing layer 20 (average thickness of only the convex portion 24 portion) is preferably 25 μm, more preferably 30 μm, and even more preferably 50 μm. On the other hand, the upper limit of the average thickness of the polishing layer 20 is preferably 4000 μm, more preferably 3500 μm, and still more preferably 3000 μm. If the average thickness of the polishing layer 20 is less than the lower limit, the durability of the polishing layer 20 may be insufficient. On the contrary, if the average thickness of the polishing layer 20 exceeds the upper limit, the homogeneity of the polishing layer 20 is lowered, and it may be difficult to exhibit a stable grinding force. In addition, the abrasive 1 may become unnecessarily thick, making it difficult to handle and increasing manufacturing costs.

<First polishing part>
The 1st grinding | polishing part 21 contains the abrasive grain 21a and its binder 21b. Although it does not specifically limit as a planar view shape of the said 1st grinding | polishing part 21, It can be made into a square shape or a circular shape. The plurality of first polishing parts 21 are arranged in a regular block pattern.

(Abrasive grains)
Examples of the abrasive grains 21a of the first polishing section 21 include diamond abrasive grains, alumina abrasive grains, silica abrasive grains, ceria abrasive grains, silicon carbide abrasive grains, and boron carbide abrasive grains.

As a minimum of content of the above-mentioned abrasive grain 21a in the 1st polish part 21, 50 volume% is preferred and 60 volume% is more preferred. On the other hand, the upper limit of the content of the abrasive grains 21a is preferably 85% by volume, and more preferably 80% by volume. When the content of the abrasive grains 21a is less than the lower limit, the content of the binder 21b is relatively increased, so that the abrasive grains 21a are firmly fixed and hardly spilled. For this reason, the crushing of the abrasive grains 21a exposed on the surface of the first polishing section 21 is likely to proceed, and the polishing rate may be reduced. Conversely, if the content of the abrasive grains 21a exceeds the upper limit, the content of the binder 21b is relatively small, and the abrasive grains 21a are likely to spill. For this reason, there is a possibility that the polishing rate may decrease due to this spillage.

The average particle diameter of the abrasive grains 21a of the first polishing section 21 is appropriately selected from the viewpoint of the polishing rate and the surface roughness of the workpiece after polishing. The lower limit of the average particle diameter of the abrasive grains 21a is preferably 1 μm and more preferably 2 μm. On the other hand, the upper limit of the average particle diameter of the abrasive grains 21a is preferably 45 μm, and more preferably 40 μm. When the average particle diameter of the abrasive grains 21a is less than the lower limit, the grinding force of the abrasive 1 is insufficient, and the processing efficiency may be reduced. Conversely, if the average particle diameter of the abrasive grains 21a exceeds the upper limit, the polishing accuracy may be reduced. Here, the “average particle size” refers to a 50% value (50% particle size, D50) of a volume-based cumulative particle size distribution curve measured by a laser diffraction method or the like.

The abrasive grains 21a of the first polishing section 21 may be composed of one type of abrasive grains, but are preferably composed of a plurality of types of abrasive grains. Thus, by constituting the abrasive grains 21a of the first polishing section 21 with a plurality of types of abrasive grains, it is possible to improve the grinding force while suppressing an increase in the manufacturing cost of the abrasive 1.

When the abrasive grains 21a are constituted by a plurality of types of abrasive grains, the abrasive grains 21a preferably include diamond abrasive grains, and in particular, the abrasive grains 21a are preferably constituted by diamond abrasive grains and alumina abrasive grains. . Diamond abrasive grains have higher grinding power than other abrasive grains, but are expensive. For this reason, grinding force can further be improved, suppressing the increase in manufacturing cost by using one type of multiple types of abrasive grains as diamond abrasive grains. In addition, since alumina abrasive grains are relatively inexpensive, the effect of reducing the manufacturing cost can be enhanced by configuring the abrasive grains 21a with diamond grindstones and alumina abrasive grains.

The diamond of the diamond abrasive grains may be single crystal or polycrystalline, or may be diamond that has been treated with Ni coating or the like. Of these, single crystal diamond and polycrystalline diamond are preferable. Single crystal diamond is hard among diamonds and has high grinding power. In addition, since polycrystalline diamond is easy to cleave in a microcrystalline unit constituting the polycrystal and does not easily crush, the decrease in the polishing rate is small.

When the abrasive grains 21a are composed of a plurality of types of abrasive grains including diamond abrasive grains, the lower limit of the content of diamond abrasive grains in the first polishing section 21 is preferably 1% by volume, more preferably 2% by volume. preferable. On the other hand, the upper limit of the content of the diamond abrasive is preferably 20% by volume, more preferably 8% by volume. If the content of the diamond abrasive grains is less than the lower limit, the grinding force of the abrasive 1 may be insufficient. On the other hand, if the content of the diamond abrasive grains exceeds the upper limit, the effect of suppressing the increase in the manufacturing cost of the abrasive 1 may be insufficient.

When the abrasive grains 21a are composed of a plurality of types of abrasive grains including diamond abrasive grains, the average grain diameter of the diamond abrasive grains is larger than the average grain diameter of other abrasive grains excluding the diamond abrasive grains. Is preferred. The lower limit of the ratio of the average particle diameter of the diamond abrasive grains to the average particle diameter of other abrasive grains excluding the diamond abrasive grains is preferably 1.3 and more preferably 1.5. On the other hand, the upper limit of the ratio of the average particle diameter is preferably 20, and more preferably 10. When the ratio of the average particle diameter is less than the lower limit, the polishing pressure applied to the abrasive grains other than the diamond abrasive grains is increased, and the polishing pressure applied to the diamond abrasive grains having a high grinding force is relatively reduced. May decrease. On the other hand, if the ratio of the average particle diameter exceeds the upper limit, abrasive grains other than diamond abrasive grains are excessively spilled, so that the abrasion of the first polishing portion 21 progresses quickly due to the spillage. The life of 1 may be shortened.

(binder)
Although it does not specifically limit as a main component of the binder 21b of the 1st grinding | polishing part 21, For example, it can be set as resin or an inorganic substance.

Examples of the resin include resins such as polyurethane, polyphenol, epoxy, polyester, cellulose, ethylene copolymer, polyvinyl acetal, polyacryl, acrylic ester, polyvinyl alcohol, polyvinyl chloride, polyvinyl acetate, and polyamide. The resin may be at least partially crosslinked.

In addition, examples of the inorganic substance include silicate, phosphate, and polyvalent metal alkoxide.

The main component of the binder 21b is preferably an inorganic substance. Among them, a silicate having a high abrasive grain holding power is preferable. Examples of such silicates include sodium silicate and potassium silicate.

The binder 21b may appropriately contain various auxiliaries and additives such as a dispersant, a coupling agent, a surfactant, a lubricant, an antifoaming agent, and a colorant depending on the purpose.

As a minimum of the average area of each 1st grinding | polishing

part

21, 1 mm < ² > is preferable and 2 mm < ² > is more preferable. In contrast, the upper limit of the average area of the first polishing section 21 is preferably 150 mm ^2, 130 mm ² and more preferably. There exists a possibility that the 1st grinding | polishing part 21 may peel from the base material 10 as the average area of the said 1st grinding | polishing part 21 is less than the said minimum. Conversely, when the average area of the first polishing portion 21 exceeds the upper limit, the number of the first polishing portions 21 that come into contact with the workpiece during polishing decreases. For example, there may be a difference in the contact area between the workpiece and the first polishing portion 21 when the periphery of the workpiece is positioned on the first polishing portion 21 and when it is positioned on the groove 23. When the number of first polishing parts 21 that come into contact with the cut body decreases, this difference tends to increase. For this reason, the polishing pressure applied to the individual abrasive grains 21a during the polishing tends to fluctuate, and the polishing accuracy may be reduced.

The lower limit of the occupied area ratio of the first polishing portion 21 in the polishing layer 20 is preferably 3%, and more preferably 4%. On the other hand, the upper limit of the occupied area ratio of the first polishing portion 21 is preferably 16%, more preferably 10%, and further preferably 9.5%. If the occupation area ratio of the first polishing portion 21 is less than the lower limit, the polishing pressure applied to the first polishing portion 21 during polishing is excessively increased, and the abrasive grains 21a are likely to fall off, which may reduce the polishing rate. is there. On the contrary, if the occupation area ratio of the first polishing unit 21 exceeds the upper limit, the polishing rate improvement effect due to the increase of the polishing pressure of the first polishing unit 21 may be insufficient.

The lower limit of the distance between adjacent first polishing parts 21 (the distance between the centers of the first polishing parts 21) is preferably 3 mm, and more preferably 5 mm. On the other hand, as an upper limit of the distance between the said 1st grinding | polishing parts 21, 50 mm is preferable and 40 mm is more preferable. When the distance between the first polishing parts 21 is less than the lower limit, it is difficult to reduce the area of each first polishing part 21 while suppressing the peeling from the base material 10. The occupied area ratio of the portion 21 cannot be sufficiently lowered, and the polishing rate improvement effect may be insufficient. On the contrary, if the distance between the first polishing parts 21 exceeds the upper limit, the occupation area ratio of the first polishing part 21 decreases too much, the wear of the first polishing part 21 progresses quickly, and the life of the abrasive 1 is increased. May be shortened.

The lower limit of the amount of wear of the first polishing portion 21 in the Taber abrasion test is preferably 0.05 g, and more preferably 0.08 g. On the other hand, the upper limit of the wear amount of the first polishing portion 21 in the Taber abrasion test is preferably 0.15 g, and more preferably 0.13 g. If the wear amount of the first polishing portion 21 is less than the lower limit, the abrasive grains 21a are less likely to spill. For this reason, the crushing of the abrasive grains 21a exposed on the surface of the first polishing section 21 is likely to proceed, and the polishing rate may be reduced. Conversely, if the amount of wear of the first polishing portion 21 exceeds the upper limit, the life of the abrasive 1 may be shortened. The amount of wear of the first polishing unit 21 can be controlled mainly by the content of the abrasive grains 21a of the first polishing unit 21 and the type of the binder 21b.

<Second polishing section>
The 2nd grinding | polishing part 22 contains the abrasive grain 22a and its binder 22b. The second polishing unit 22 surrounds the entire circumference of the first polishing unit 21, and the inner circumference thereof coincides with the circumference of the first polishing unit 21. That is, the shape formed by the inner periphery of the second polishing unit 22 is the same shape as the plan view of the first polishing unit 21. Further, the shape constituted by the outer periphery of the second polishing portion 22 (the shape in plan view of the convex portion 24) is not particularly limited, but the center of gravity coincides with that of the first polishing portion 21 as shown in FIG. It can be made into a simple shape.

(Abrasive grains)
Examples of the abrasive grains 22a of the second polishing section 22 include the same abrasive grains as the abrasive grains 21a of the first polishing section 21.

As a minimum of content of the above-mentioned abrasive grain 22a in the 2nd polish part 22, 60 volume% is preferred and 70 volume% is more preferred. On the other hand, the upper limit of the content of the abrasive grains 22a is preferably 95% by volume, and more preferably 80% by volume. When the content of the abrasive grains 22a is less than the lower limit, the content of the binder 22b is relatively increased, so that the abrasive grains 22a are firmly fixed and hardly spilled. For this reason, the wear amount of the second polishing portion 22 is reduced, and a difference in wear amount between the first polishing portion 21 and the first polishing portion 21 is less likely to occur during polishing. As a result, the polishing pressure of the first polishing unit 21 cannot be sufficiently increased, and the effect of improving the polishing rate may be insufficient. On the other hand, if the content of the abrasive grains 22a exceeds the upper limit, the content of the binder 22b is insufficient and the abrasive grains 22a cannot be sufficiently fixed, and thus the second polishing portion 22 may be easily damaged during polishing. is there.

Further, the content of the abrasive grains 22 a in the second polishing section 22 is preferably larger than the content of the abrasive grains 21 a in the first polishing section 21. Wear of the first polishing unit 21 and the second polishing unit 22 proceeds mainly due to spilling of abrasive grains, and wear tends to occur when the content of abrasive grains is large. For this reason, by making the content of the abrasive grains 22 a in the second polishing section 22 greater than the content of the abrasive grains 21 a in the first polishing section 21, the wear amount of the second polishing section 22 is reduced to the wear of the first polishing section 21. Control can be facilitated to be larger than the amount.

The lower limit of the content difference between the abrasive grains 22a in the second polishing section 22 and the abrasive grains 21a in the first polishing section 21 is preferably 5% by volume, and more preferably 7% by volume. On the other hand, the upper limit of the content difference is preferably 20% by volume, and more preferably 15% by volume. When the difference in content is less than the lower limit, it becomes difficult to control the ratio of the wear amount between the first polishing part 21 and the second polishing part 22, and polishing by increasing the polishing pressure of the first polishing part 21 is performed. The rate improvement effect may be insufficient. On the contrary, if the difference in content exceeds the upper limit, the content of the abrasive grains 22a in the second polishing unit 22 may be excessively increased and the second polishing unit 22 may be easily damaged, or in the first polishing unit 21. There is a possibility that the content of the abrasive grains 21a becomes too small and the polishing rate is lowered.

The average particle diameter of the abrasive grains 22 a of the second polishing unit 22 is appropriately selected from the viewpoint of controllability of the wear amount of the second polishing unit 22. The lower limit of the average particle diameter of the abrasive grains 22a is preferably 1 μm and more preferably 2 μm. On the other hand, the upper limit of the average particle diameter of the abrasive grains 22a is preferably 20 μm and more preferably 15 μm. If the average particle diameter of the abrasive grains 22a is less than the lower limit, the abrasive grains 22a are likely to spill over, and the control of the wear amount of the second polishing section 22 may be difficult. Conversely, when the average particle diameter of the abrasive grains 22a exceeds the upper limit, the difference between the height difference between the first polishing section 21 and the second polishing section 22 formed during polishing and the average particle diameter of the abrasive grains 22a. Becomes too small, the abrasive grains 22a of the second polishing section 22 come into contact with the workpiece, and the ratio of contribution to grinding increases. For this reason, the polishing load is dispersed in the first polishing unit 21 and the second polishing unit 22, and the polishing rate improvement effect due to the increase in the polishing pressure of the first polishing unit 21 may be insufficient.

The abrasive grains 22a of the second polishing unit 22 may be composed of one kind of abrasive grains or a plurality of kinds of abrasive grains.

The upper limit of the content of diamond abrasive grains in the second polishing section 22 is preferably 0.3% by volume, and more preferably 0.2% by volume. Since diamond abrasive grains are hard and have high grinding power, clogging and spilling are less likely to occur even when they come into contact with the workpiece, and are more susceptible to large polishing loads than other abrasive grains. For this reason, when the content of diamond abrasive grains in the second polishing portion 22 exceeds the upper limit, a polishing load applied to the second polishing portion 22 during polishing increases. As a result, the polishing load is dispersed in the first polishing unit 21 and the second polishing unit 22, and the polishing rate improvement effect due to the increase in the polishing pressure of the first polishing unit 21 may be insufficient. Moreover, since the said abrasive | polishing material 1 mainly grind | polishes by the 1st grinding | polishing part 21, there exists a possibility that the grinding force improvement effect obtained may become inadequate with respect to the raise of the manufacturing cost of the said abrasive | polishing material 1. FIG. On the other hand, the lower limit of the content of the diamond abrasive grains is not particularly limited, and is 0% by volume, that is, the second polishing portion 22 may not contain diamond abrasive grains.

(binder)
Examples of the main component of the binder 22b of the second polishing unit 22 include the same components as the main component of the binder 21b of the first polishing unit 21. Especially, as a main component of the binder 22b of the 2nd grinding | polishing part 22, polyacryl, an epoxy, polyester, and a polyurethane are preferable. These resins are easy to ensure good adhesion to the substrate 10. In addition, since these resins have a lower abrasive holding power than inorganic materials, the abrasive grains 22a spill out moderately, and the amount of wear of the second polishing section 22 can be easily controlled.

The binder 22b may appropriately contain various auxiliaries and additives such as a dispersant, a coupling agent, a surfactant, a lubricant, an antifoaming agent, and a coloring agent depending on the purpose.

The lower limit of the occupied area ratio of the second polishing portion 22 in the polishing layer 20 is preferably 5%, and more preferably 15%. On the other hand, the upper limit of the occupation area ratio of the second polishing portion 22 is preferably 97%, and more preferably 95%. When the occupation area ratio of the second polishing portion 22 is less than the lower limit, the effect of suppressing damage due to the drop of the work body into the groove 23 may be insufficient. On the contrary, if the occupation area ratio of the second polishing section 22 exceeds the upper limit, the occupation area ratio of the first polishing section 21 is relatively reduced, so that the wear of the first polishing section 21 is promoted and the first A difference in height between the polishing unit 21 and the second polishing unit 22 is less likely to occur. As a result, the polishing pressure of the first polishing unit 21 cannot be sufficiently increased, and the effect of improving the polishing rate may be insufficient.

The lower limit of the occupied area ratio of the entire polishing part in the polishing layer 20 (the sum of the occupied area ratios of the first polishing part 21 and the second polishing part 22) is 15%, more preferably 16%, 25 % Is more preferable. When the occupation area ratio of the entire polishing portion is less than the lower limit, there is a possibility that damage due to the drop of the workpiece into the groove or the like may occur. On the other hand, the upper limit of the occupied area ratio of the entire polishing portion is 100%. In addition, when the occupation area ratio of the whole polishing unit is 100%, the polishing layer 20 does not have the groove 23 and is configured only by the first polishing unit 21 and the second polishing unit 22.

The lower limit of the amount of wear of the second polishing portion 22 in the Taber abrasion test is preferably 0.3 g, more preferably 0.4 g. If the wear amount of the second polishing portion 22 is less than the lower limit, a difference in height due to the difference in wear amount between the first polishing portion 21 and the first polishing portion 21 is less likely to occur during polishing. As a result, the polishing pressure of the first polishing unit 21 cannot be sufficiently increased, and the effect of improving the polishing rate may be insufficient. On the other hand, the upper limit of the wear amount of the second polishing portion 22 is not particularly limited, but is usually about 0.8 g.

The lower limit of the ratio of the wear amount of the second polishing portion 22 to the wear amount of the first polishing portion 21 in the Taber abrasion test is 3, more preferably 3.5, and even more preferably 4. If the wear amount ratio is less than the lower limit, a step due to the difference in wear amount is less likely to occur with the first polishing portion 21 during polishing. As a result, the polishing pressure of the first polishing unit 21 cannot be sufficiently increased, and the effect of improving the polishing rate may be insufficient. On the other hand, the upper limit of the wear amount ratio is not particularly limited, and is about 15.

Before the polishing material 1 is used for polishing, the first polishing portion 21 and the second polishing portion 22 may have the same surface and no step as shown in FIG. A step, that is, a step having an average height of 30 μm or more and 60 μm or less may be provided in advance.

<Groove>
The grooves 23 are arranged on the surface of the polishing layer 20 in a lattice pattern with equal intervals. Further, the bottom surface of the groove 23 is constituted by the surface of the base material 10.

The upper limit of the average width of the groove 23 is preferably 10 mm, and more preferably 8 mm. If the average width of the groove 23 exceeds the upper limit, the occupation area ratio of the convex portion 24 cannot be sufficiently ensured, and the work body is likely to fall into the groove 23 during polishing, so that the work body may be damaged. There is. On the other hand, the lower limit of the average width of the groove 23 is not particularly limited, and may be 0 mm, that is, the abrasive 1 may not have the groove 23.

(Adhesive layer)
The adhesive layer 30 is a layer that supports the abrasive 1 and fixes the abrasive 1 to a support for mounting on the polishing apparatus.

The adhesive used for the adhesive layer 30 is not particularly limited, and examples thereof include a reactive adhesive, an instantaneous adhesive, a hot melt adhesive, and a pressure-sensitive adhesive that can be replaced.

As the adhesive used for the adhesive layer 30, a pressure-sensitive adhesive is preferable. By using a pressure-sensitive adhesive as the adhesive used for the adhesive layer 30, the abrasive 1 can be peeled off from the support and can be replaced, so that the abrasive 1 and the support can be easily reused. Such an adhesive is not particularly limited. For example, an acrylic adhesive, an acrylic-rubber adhesive, a natural rubber adhesive, a synthetic rubber adhesive such as butyl rubber, a silicone adhesive, and a polyurethane adhesive. Agents and the like.

The lower limit of the average thickness of the adhesive layer 30 is preferably 0.05 mm, more preferably 0.1 mm. Moreover, as an upper limit of the average thickness of the contact bonding layer 30, 0.3 mm is preferable and 0.2 mm is more preferable. When the average thickness of the adhesive layer 30 is less than the above lower limit, the adhesive force is insufficient, and the abrasive 1 may be peeled off from the support. On the other hand, when the average thickness of the adhesive layer 30 exceeds the above upper limit, for example, due to the thickness of the adhesive layer 30, there is a possibility that workability may be deteriorated, for example, when the abrasive 1 is cut into a desired shape.

[Production method of abrasive]
The abrasive 1 includes a step of preparing a first polishing portion composition, a step of preparing a second polishing portion composition, and forming the first polishing portion 21 by printing the first polishing portion composition. And the step of forming the second polishing portion 22 by printing the second polishing portion composition, and the step of laminating the adhesive layer 30 on the back side of the substrate 10.

First, in the first polishing part composition preparing step, a solution in which the first polishing part composition (the material for forming the abrasive grains 21a and the binder 21b of the first polishing part 21) is dispersed in a solvent is prepared as a coating liquid. To do. The solvent is not particularly limited as long as the material for forming the binder 21b is soluble. Specifically, methyl ethyl ketone (MEK), isophorone, terpineol, N methylpyrrolidone, cyclohexanone, propylene carbonate, or the like can be used. In order to control the viscosity and fluidity of the coating liquid, a diluent such as water, alcohol, ketone, acetate ester and aromatic compound may be added.

Next, in the second polishing part composition preparing step, in the same manner as the coating liquid in the first polishing part composition preparing step, the second polishing part composition (the abrasive grains 22a of the second polishing part 22 and the second polishing part 22). A solution in which a material for forming the binder 22b is dispersed in a solvent is prepared as a coating liquid. In addition, you may perform this composition preparation process for 2nd grinding | polishing parts before the composition preparation process for 1st grinding | polishing parts, or after a 1st grinding | polishing part formation process.

Next, in the first polishing part forming step, a plurality of first polishing parts 21 are formed on the surface of the base material 10 by a printing method using the coating liquid prepared in the first polishing part composition preparing step. Specifically, a mask having a shape corresponding to the inverted shape of the first polishing portion 21 is prepared, and the coating liquid is printed through the mask. As this printing method, for example, screen printing, metal mask printing or the like can be used.

The first polishing part 21 is formed by heat-dehydrating and heat-curing the printed coating liquid. Specifically, after drying and heat-dehydrating the coating liquid at room temperature (25 ° C.), the first polishing part 21 is formed by heat-curing.

Next, in the second polishing portion forming step, the second polishing portion 22 surrounding the first polishing portion 21 is formed by a printing method using the coating liquid prepared in the second polishing portion composition preparing step. Specifically, a mask having a shape corresponding to the inverted shape of the second polishing unit 22 is prepared, and the coating liquid is printed through the mask. As this printing method, for example, squeegee printing, bar coater printing, applicator printing, or the like can be used. The second polishing portion forming step can be performed before the first polishing portion forming step or simultaneously with the first polishing portion forming step.

The second polishing part 22 is formed by heat-curing the printed coating solution. Specifically, the second polishing part 22 is formed by heating and curing the coating liquid.

Finally, in the adhesive layer stacking step, the adhesive layer 30 is stacked on the back side of the substrate 10. Specifically, for example, a previously formed tape-like adhesive layer 30 is attached to the back surface of the substrate 10. In addition, this adhesion layer lamination process can also be performed before the 2nd grinding | polishing part formation process.

〔advantage〕
The abrasive 1 includes a first polishing unit 21 and a second polishing unit 22 surrounding the first polishing unit 21, and the second polishing unit 22 has a wear amount of the first polishing unit 21 in a Taber abrasion test. The wear amount ratio is 3 or more. For this reason, when polishing is performed using the abrasive 1, the second polishing portion 22 surrounding the first polishing portion 21 is worn first. As a result, in a relatively short time from the start of polishing, a step is formed between the first polishing unit 21 and the second polishing unit 22 so that the second polishing unit 22 has a low height. Further, since the abrasion of the polishing part proceeds mainly in both the first polishing part 21 and the second polishing part 22 due to spilling of abrasive grains, the work piece is polished while maintaining this step. Accordingly, since the first polishing portion 21 mainly receives a polishing load applied at the time of polishing, the polishing pressure of the first polishing portion 21 is increased, and thereby the grinding force of the abrasive 1 is increased. In the abrasive 1, the second polishing portion 22 surrounds the first polishing portion 21, and the occupation area ratio of the entire polishing portion in the polishing layer 20 is 15% or more and 100% or less. For this reason, the abrasive 1 can prevent the workpiece from being inclined toward the substrate by the second polishing portion 22 when the end of the workpiece moves between the first polishing portions 21 during polishing. Therefore, the abrasive 1 can suppress damage due to the drop of the workpiece into the groove 23 and the like.

[Other Embodiments]
The present invention is not limited to the above-described embodiment, and can be implemented in a mode in which various changes and improvements are made in addition to the above-described mode.

In the above embodiment, the case where the plurality of first polishing parts are regularly arranged in a block pattern has been described, but the arrangement of the plurality of first polishing parts is not limited to this. For example, the plurality of first polishing units may be arranged at different intervals in the orthogonal X direction and Y direction.

In the above-described embodiment, the grooves are configured in a lattice pattern with equal intervals, but the lattice spacing and the planar shape are not limited to those in the above-described embodiment. Moreover, in the said embodiment, although the bottom face of the groove | channel was set as the structure which is the surface of a base material, the depth of a groove | channel is smaller than the average thickness of a grinding | polishing layer, and a groove | channel does not need to reach the surface of a base material.

In the above embodiment, the configuration in which the groove separates the second polishing portion has been described, but the configuration of the groove is not limited to this. For example, as shown in FIG. 3, the groove 23 may be disposed between the first polishing unit 21 and the second polishing unit 22. In this case, the groove 23 may be disposed so as to surround the first polishing portion 21, but may be disposed so as to be in contact with a part of the first polishing portion 21.

Further, the abrasive may have a structure without a groove.

In the above embodiment, the case where the shape constituted by the outer periphery of the second polishing unit is similar to the first polishing unit has been described, but the shape of the second polishing unit is similar to the first polishing unit. It is not limited. For example, as shown in FIG. 4, the first polishing portion 21 may be circular, and the shape constituted by the outer periphery of the second polishing portion 22 may be rectangular.

In the above embodiment, the case where one second polishing unit surrounds one first polishing unit has been described. However, even if one second polishing unit 22 surrounds a plurality of first polishing units 21 as shown in FIG. Good.

Further, the second polishing unit may not surround the entire circumference of the first polishing unit, and may have a notch in a part as shown in FIG. In addition, from the viewpoint of suppressing damage due to a drop in the cutout of the work body, the length of the portion facing the second polishing portion 22 in the entire circumference of the first polishing portion 21 is 90% or more, preferably 95% or more. It is.

In the above embodiment, the case where the polishing layer has two types of polishing portions having different wear amounts in the Taber abrasion test has been described, but the polishing layer may have three or more types of polishing portions. In this case, the polishing portion with the smallest amount of wear is the first polishing portion, and the remaining two or more polishing portions are the other polishing portions (corresponding to the second polishing portion in the above embodiment). The configuration of the other polishing unit is not particularly limited as long as the first polishing unit is surrounded by the other polishing unit. As another configuration of the polishing unit, for example, as shown in FIG. 7, the first polishing unit 21 is surrounded by the first other polishing unit 25, and the first other polishing unit 25 is the second other polishing unit. The configuration surrounded by the polishing unit 26, as shown in FIG. 8, the first other polishing unit 25 and the second other polishing unit 26 are alternately arranged along the circumference of the first polishing unit 21, The structure etc. which the 1st grinding | polishing part 21 is cyclically enclosed by the whole other grinding | polishing part arrange | positioned by turns can be mentioned.

Furthermore, as shown in FIG. 9, the abrasive 2 may include a support 40 laminated via an adhesive layer 30 on the back side and a second adhesive layer 31 laminated on the back side of the support 40. . When the abrasive 2 includes the support 40, the handling of the abrasive 2 is facilitated.

Examples of the main component of the support 40 include thermoplastic resins such as polypropylene, polyethylene, polytetrafluoroethylene, and polyvinyl chloride, and engineering plastics such as polycarbonate, polyamide, and polyethylene terephthalate. By using such a material as the main component of the support 40, the support 40 has flexibility, the abrasive 2 follows the surface shape of the workpiece, and the polishing surface, the workpiece, Since it becomes easy to contact, a polishing rate improves further.

The average thickness of the support 40 can be, for example, 0.5 mm or more and 3 mm or less. When the average thickness of the support 40 is less than the lower limit, the strength of the abrasive 2 may be insufficient. On the other hand, when the average thickness of the support 40 exceeds the upper limit, it may be difficult to attach the support 40 to a polishing apparatus or the flexibility of the support 40 may be insufficient.

The second adhesive layer 31 can use the same adhesive as the adhesive layer 30. The second adhesive layer 31 can have an average thickness similar to that of the adhesive layer 30.

Hereinafter, the present invention will be described in more detail with reference to examples and comparative examples, but the present invention is not limited to the following examples.

[Example 1]
Diamond abrasive grains (55% by mass nickel-coated diamond, average particle diameter 35 μm), alumina abrasive grains (Al ₂ O ₃ , fused alumina, average particle diameter 12 μm), and silicate (No. 3 sodium silicate) as a binder ), And the content of diamond abrasive grains in the first polishing part is 5% by volume and the content of alumina abrasive grains in the first polishing part is 71% by volume. A coating solution was obtained.

Also, alumina abrasive grains (white alumina WA # 1000, average particle size 12 μm), epoxy as binder (“TB2022” from Three Bond Holdings Co., Ltd.), and epoxy curing agent (“TB2105C” from Three Bond Holdings Co., Ltd.) are mixed. Then, the content of the alumina abrasive grains in the second polishing part was adjusted to 85% by volume to obtain a coating liquid for the composition for the second polishing part.

An aluminum plate having an average thickness of 300 μm was prepared as a base material, and a plurality of first polishing parts were formed on the surface of the base material by printing using the coating liquid for the first polishing part composition. The plurality of first polishing parts are in a regularly arranged block pattern, and the distance between the centers of adjacent first polishing parts is 10 mm. For printing, a mask having a pattern corresponding to the inverted shape of the first polishing portion was used. Each of the first polishing portions had an area of 9 mm ² (a square shape with a side of 3 mm in plan view), and the average thickness of the first polishing portions was 500 μm. The area occupancy in the polishing layer of the first polishing part was 9%.

The coating solution was dried at room temperature (25 ° C.) and heated and dehydrated, and then cured by heating.

Further, a hard vinyl chloride resin plate having an average thickness of 1 mm is used as a support that supports the substrate and is fixed to the polishing apparatus, and the back surface of the substrate and the surface of the support are bonded with an adhesive having an average thickness of 130 μm. Combined. A double-sided tape (“# 5605HGD” from Sekisui Chemical Co., Ltd.) was used as the adhesive.

Next, the 2nd grinding | polishing part was formed by printing so that the 1st grinding | polishing part might be surrounded using the coating liquid of the said composition for 2nd grinding | polishing parts. Each 2nd grinding | polishing part was made into the area 81mm < ² > (The square shape whose outer periphery is 9.5 mm on one side in planar view). The average thickness of the second polishing part was the same as the average thickness of the first polishing part. The area occupation ratio in the polishing layer of the second polishing portion was 81%, and the area occupation ratio of the entire polishing portion in the polishing layer was 90%. In addition, 10% of the remaining part of the polishing layer is a groove, and the groove has a lattice shape with an average width of 0.5 mm.

The coating solution was dried by heating. In this way, an abrasive of Example 1 was obtained.

[Examples 2 and 3, Comparative Example 3]
Example 2 and Example 3 in the same manner as in Example 1 except that the occupation area ratio of the first polishing section, the occupation area ratio of the second polishing section, and the occupation area ratio of the entire polishing section were set to the values shown in Table 1. An abrasive was obtained.

[Example 4]
Diamond abrasive grains (55% by weight nickel-coated diamond, average particle diameter 35 μm), alumina abrasive grains (white alumina WA # 1000, average particle diameter 12 μm), epoxy as a binder (“TB2022” of Three Bond Holdings Co., Ltd.), and An epoxy curing agent (“TB2105C” manufactured by Three Bond Holdings Co., Ltd.) was mixed, and the content of diamond abrasive grains in the second polishing portion was 0.2% by volume, and the content of alumina abrasive grains in the second polishing portion was 84.%. It prepared so that it might become 8 volume%, and obtained the coating liquid of the composition for 2nd grinding | polishing parts.

The abrasive of Example 4 was obtained in the same manner as in Example 1 except that the second polishing part composition was used.

[Example 5]
The area occupancy in the polishing layer of the second polishing part was 91%, the area occupancy of the entire polishing part in the polishing layer was 100%, and the polishing layer did not have a groove. Thus, an abrasive of Example 5 was obtained.

[Example 6]
Alumina abrasive grains (white alumina WA # 1000, average particle diameter 12 μm) and acrylic as a binder (“Dianar BR-80” manufactured by Mitsubishi Rayon Co., Ltd.) are mixed, and the content of alumina abrasive grains in the second polishing part Was prepared to be 85% by volume to obtain a coating liquid for the second polishing portion composition.

The abrasive of Example 6 was obtained in the same manner as Example 5 except that the second polishing part composition was used.

[Comparative Example 1]
Silicon carbide abrasive grains (green carbonite, average particle diameter 30 μm), alumina abrasive grains (white alumina WA # 1000, average particle diameter 12 μm), and silicate (No. 3 sodium silicate) as a binder are mixed, and silicon carbide is mixed. The content of the abrasive grains in the second polishing part is 30% by volume, and the content of the alumina abrasive grains in the second polishing part is 46% by volume to obtain a coating liquid for the composition for the second polishing part. It was.

A polishing material of Comparative Example 1 was obtained in the same manner as Example 5 except that the second polishing part composition was used.

[Comparative Example 2]
Diamond abrasive grains (55 mass% nickel-coated diamond, average particle diameter 35 μm), alumina abrasive grains (white alumina WA # 1000, average particle diameter 12 μm), and silicate (No. 3 sodium silicate) as a binder are mixed. The composition for the second polishing part was prepared such that the content of silicon carbide abrasive grains in the second polishing part was 2.5% by volume and the content of alumina abrasive grains in the second polishing part was 77.5% by volume. A product coating solution was obtained.

A polishing material of Comparative Example 2 was obtained in the same manner as in Example 1 except that the second polishing part composition was used.

[Polishing conditions]
The sapphire substrate was polished using the abrasives obtained in Examples 1 to 6 and Comparative Examples 1 to 3. As the sapphire substrate, a c-plane sapphire substrate having a diameter of 5.08 cm and a specific gravity of 3.97 was used. A known double-side polishing machine was used for the polishing. The carrier of the double-side polishing machine is 0.4 mm thick epoxy glass. Polishing was performed under the conditions of a polishing pressure of 200 g / cm ² , an upper surface plate rotation speed of 25 rpm, a lower surface plate rotation speed of 50 rpm, and a SUN gear rotation speed of 8 rpm. At that time, 30 cc of “Daffney Cut GS50K” manufactured by Idemitsu Kosan Co., Ltd. was supplied as a coolant.

[Evaluation methods]
About the abrasives of Examples 1 to 6 and Comparative Examples 1 to 3, the amount of wear by the Taber abrasion test, and the first and second polishing parts when the sapphire substrate was polished using these abrasives, The average height of the step and the polishing rate were measured. The results are shown in Table 1.

<Measurement of wear>
For the measurement of the abrasion amount by the Taber abrasion test, two abrasive materials of Examples 1 to 6 and Comparative Examples 1 to 3 were prepared. Of these two abrasives, the second abrasive part is removed from one abrasive, and the abrasive of only the first abrasive part is used. The first abrasive part is removed from the other abrasives, and the second abrasive part Only the abrasive was used. Test pieces (average diameter 104 mm, average thickness 300 μm) are prepared from the above two abrasives, and each test piece is subjected to wear wheel H-18, load using a Taber abrasion tester (“MODEL174” manufactured by Taber Instrument). It was made to wear by rotating 320 times under the condition of 4.9 N (500 gf). The mass difference [g] between the test pieces before and after 320 rotations was measured and used as the wear amount [g].

<Measurement of average height of steps>
The average height of the step between the first polishing part and the second polishing part was determined as an average value of the obtained measurement values by measuring any 15 points using a laser displacement meter (manufactured by Keyence Corporation). .

<Polishing rate>
Regarding the polishing rate, the sapphire substrate was polished for 10 minutes, and the weight change (g) of the substrate before and after polishing was divided by the substrate surface area (cm ² ), the specific gravity of the substrate (g / cm ³ ), and the polishing time (minutes). The unit was calculated in terms of μm / min.

In Table 1, “−” in the curing agent and the second abrasive means that the curing agent and the second abrasive are not used, respectively. Further, “−” in the average height of the step and the polishing rate means that the measurement was not possible because the substrate was damaged by dropping into the groove of the substrate.

From the results in Table 1, the polishing materials of Examples 1 to 6 have a higher polishing rate than the polishing materials of Comparative Examples 1 to 3. On the other hand, the abrasives of Comparative Examples 1 and 2 have a wear ratio in the Taber abrasion test of the first polishing part with respect to the second polishing part of less than 3, so the first polishing part and the second polishing are polished during polishing. There is no sufficient level difference between the two parts. For this reason, in the polishing using the abrasives of Comparative Examples 1 and 2, the polishing load was dispersed in the first polishing portion and the second polishing portion, so that the polishing pressure of the first polishing portion did not increase and the polishing rate was low. Conceivable. In addition, since the polishing material of Comparative Example 3 has an area occupation ratio of the entire polishing portion of less than 15%, it is considered that damage due to the drop of the workpiece into the groove occurred.

From the above, by setting the ratio of the wear amount of the second polishing part to 3 or more in the Taber abrasion test of the first polishing part, the occupation area ratio of the entire polishing part in the polishing layer is 15% or more and 100% or less, It can be seen that high machining efficiency can be achieved while suppressing damage due to the drop of the workpiece into the groove or the like.

The abrasive of the present invention can achieve a relatively high processing efficiency while suppressing damage caused by dropping into the groove of the work body. Therefore, the said abrasive | polishing material is used suitably for planar grinding | polishing of substrates, such as glass and sapphire.

DESCRIPTION OF

SYMBOLS

1, 2 Abrasive material 10 Base material 20 Polishing layer 21 1st grinding | polishing part 22 2nd grinding | polishing

part

21a, 22a

Abrasive grain

21b, 22b Binder 23 Groove 24 Convex-shaped

part

25, 26 Other grinding | polishing part 30 Adhesive layer 31 2nd adhesion | attachment Layer 40 support

Claims

An abrasive comprising a substrate and a polishing layer laminated on the surface side of the substrate,
The polishing layer includes abrasive grains and a binder thereof, and has a plurality of types of polishing parts having different wear amounts in the Taber abrasion test,
Of the plurality of types of polishing parts, the first polishing part with the smallest amount of wear is surrounded by other polishing parts,
The ratio of the wear amount of the other polishing portion to the wear amount of the first polishing portion is 3 or more,
An abrasive having an occupied area ratio of the entire polishing portion in the polishing layer of 15% or more and 100% or less.
The abrasive according to claim 1, wherein an area ratio occupied by the first polishing portion in the polishing layer is 3% or more and 16% or less.
The abrasive according to claim 1 or 2, wherein the abrasive grains of the first polishing section are composed of a plurality of types of abrasive grains.
The first polishing portion includes diamond abrasive grains,
The abrasive according to claim 3, wherein the content of the diamond abrasive grains in the first polishing portion is 1% by volume or more and 20% by volume or less.
The abrasive according to any one of claims 1 to 4, wherein a content of the diamond abrasive grains in the other polishing portion is 0.3% by volume or less.